FORT HOOD, Texas (AP) — The paralysis-related health problems of the Army psychologist charged with carrying out the deadly attack on Fort Hood could significantly slow the pace of his upcoming court-martial, including delays for stretch breaks and fewer daily hours for testimony.

Maj. Nidal Hasan was left paralyzed from the abdomen down when police shot him during the Nov. 5, 2009, attack on the Texas Army post that left 13 people dead and nearly three dozen wounded. If convicted, he faces execution or life in prison.

Jury selection was to begin last week, with testimony set to start in early July. But everything was pushed back again last week, at least briefly, during a hearing in which the Army judge, Col. Tara Osborn, granted Hasan’s request to represent himself. Before she did, she warned him that doing so would be “a far more physically taxing enterprise than you can imagine.”

She’s expected to rule Tuesday on his request for a three-month delay.

While Hasan can maneuver his wheelchair, his doctor said Hasan cannot sit upright more than 12 hours a day without his concentration being affected. Inmates at Hasan’s jail must wake up before dawn, so daily testimony would have to conclude by 5 p.m. at the latest, Dr. Prasad Lakshminarasimhiah told the judge last week.

A court-martial already has the potential to take longer because military jurors are allowed to submit questions to witnesses after they have testified, so many judges allow testimony to continue until late at night, if witnesses and the jury want to keep going. But that would not be possible at Hasan’s trial.

To avoid muscle spasms, Hasan also must have 15- to 20-minute breaks for stretching every four hours. To avoid developing sores, he also must relieve pressure by lifting himself off his wheelchair for about a minute every half hour.

It’s unclear if the breaks for stretching and meals could be taken at the same time, and Fort Hood officials have not said if the trial’s daily schedule will be set with Hasan’s medical issues in mind.

Hasan, who uses a catheter and adult diapers, refuses to take medication that would help regulate his digestive system, and he must eat at the same time each day to avoid accidents, Lakshminarasimhiah said. The jail serves breakfast at about 4:30 a.m., lunch about 10:30 a.m. and dinner at about 4:30 p.m., but the American-born Muslim told the judge that he fasts frequently and misses a meal on those days.

Hasan is housed in the nearby Bell County Jail, which has a contract with Fort Hood to hold all of its defendants because the Army post does not have holding facilities.

Hasan has lost weight since his arrest; his face is gaunter than his Army photo taken before the rampage. It’s unclear if the weight loss is due to his fasting or a health problem.

In September, Hasan was hospitalized a few days for undisclosed reasons. His former defense attorney, John Galligan, said he believes Hasan was hospitalized because of problems related to his incontinence. Hasan had health problems stemming from his catheter, including blood in his urine, about a year before he was hospitalized, Galligan said.

Because he has “poor trunk support,” Hasan has difficulty writing more than a few pages at a time, and nerve damage in his left hand makes typing more challenging, his doctor told the judge.

When Osborn asked how he would write legal motions, a necessity for an attorney during a trial, Hasan answered, “I’ll do the best I can.”

Medical experts not involved in Hasan’s case say a paraplegic may be able to do the same tasks as others, but first must develop the strength and stamina over time.

“If he has not been doing (these things), sitting up for 12 hours may be stretching it,” said Dr. Rita Hamilton, director of spinal cord injury medicine for the Baylor Institute for Rehabilitation in Dallas.

In addition to ruling on Hasan’s request for a three-month trial delay on Tuesday, the judge is expected to discuss his “defense of others” strategy, which requires him to prove the shootings were necessary to protect others from imminent harm or death. Hasan told the judge that U.S. troops deploying from the Army post posed an immediate threat to Taliban leaders in Afghanistan.

Witnesses said the day of the rampage a gunman wearing an Army combat uniform shouted “Allahu Akbar!” — “God is great!” in Arabic — and opened fire in a crowded medical building where deploying soldiers get vaccines and tests. Witnesses said the gunman fired rapidly, pausing only to reload, even shooting at some soldiers as they hid under desks and fled the building.

Government documents show that in the years before the shooting, Hasan told some colleagues that the U.S. was at war with Islam. In some emails to a radical Muslim cleric, Hasan indicated that he supported terrorists and was intrigued with the idea of U.S. soldiers killing comrades in the name of Islam.